package com.agriculture.controller;

import com.agriculture.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.UUID;

/**
 * 文件上传和下载
 */
@CrossOrigin
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    private String rootPath = new File("").getAbsolutePath();
    private String parentPath = new File(rootPath).getParent();
    private String baseUrl = parentPath + "/imgs/";

    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) throws IOException {

        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        String fileName = UUID.randomUUID().toString() + suffix;

        //创建一个目录对象
        File dir = new File(baseUrl);
        //判断当前目录是否存在
        if(!dir.exists()){
            //目录不存在，需要创建
            dir.mkdirs();
        }

        log.info("图片文件夹路径在：" + baseUrl);
        try{
            file.transferTo(new File(baseUrl + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);

    }


    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){

        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(baseUrl + name));

            //输出流，通过输出流将文件写回浏览器
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }

            //关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}
